SFO-HKG. United 777 w/10 across. Economy+. 22 month old.

I worry about bringing my car seat on board. It barely fit in the Southwest flight I recently took, and the 777 seats are even narrower (sigh). And on the Southwest flight, the pax in front couldn't recline as a result... I'd hate to trigger an in cabin flight mid-Pacific.

The catch is that my kid kind of likes (tolerates?) being in the car seat. He hates laps. I picked this up the other day. Has anyone tried this before? How does your toddler sleep restrained like this?